The present invention relates to receiver/driers for fluid refrigerant circulated in refrigeration and air conditioning systems. The invention relates particularly for receiver/driers utilized in vehicle passenger compartment air conditioning systems and particularly those utilized for high volume mass production of such systems. In providing receiver/driers for high volume production of vehicle air conditioning systems, it is desired to provide lightweight and also low manufacturing cost particularly in highly competitive applications situations such as air conditioning systems for passenger cars and light trucks.
Heretofore, receiver/driers for high volume production vehicle air conditioning systems have been fabricated with canisters having a metal basket insert containing granular desiccant material with the basket covered with a perforated cover. Alternatively, the desiccant material has been prepackaged in bags, but this approach has proven to be troublesome during assembly of the receiver/drier.
In fabricating receiver/driers where the granular desiccant is disposed in a metal basket, accurate positioning of the basket cover has been required in order to provide proper communication with the inlet of the receiver/drier typically located on the canister top or header to prevent clogging and reduced flow through the receiver/drier. This latter type of construction requires accurate positioning of the basket and basket cover and has also proven to be troublesome in assembly and has resulted in increased manufacturing costs. Thus it has been desired to provide a receiver/drier for fluid refrigerant which is low in manufacturing cost, lightweight and easy to assembly in high volume mass production.
Referring to FIG. 3, a typical prior art receiver/drier for a passenger car air conditioning system is shown indicated generally at 10 wherein a header 12 is welded to the upper end of a canister 13. The header 12 has an inlet port 14 and an outlet port 16 provided therein with an elongated tube 18 attached to the inlet port 14 and which extends downwardly from the header. A metal desiccant basket 20 has granular desiccant material 22 therein which has the tube 18 passing downwardly therethrough and a layer of filter material 24 covers the desiccant and is in turn covered by a perforated cover plate 26. The upper rim of the basket is crimped over a reduced diameter portion 30 of the header to retain the basket in place. A plenum chamber or space 32 is provided above the perforated plate or cover 26 to ensure flow through the desiccant material.